Every now and then, an article pops up which argues that it would make sense for Microsoft to offer a free, ad-powered version of Windows. "We are all aware that Google is the king of online advertising. Microsoft has wanted to compete in that space forever, which is why giving away Windows 7 makes so much sense,"Business Pundit argues, "Let's look at the numbers; Microsoft's operating systems are on 90% of the world's computers, or roughly one billion machines. That's penetration on a massive scale. Even Google has to be impressed." While these articles make some valid points, they rarely dive into the actual details.

It would be VERY helpful for the truly FREE ( as in beer ) operating systems!

Of course, no self-respecting OEM would put that on their machines, so it would never happen, but still...

Pop-ups wouldn't be the right way, an integrated widget would certainly be. I'd think just making the Vista sidebar mandatory, and only allow it to display rotating ads - while requiring an internet connection, and configure it so that no window could cover it would be the best use for the sidebar :-).